I have that as well, but I have been dx'd with gastroparesis. A gastric emptying scan (where you eat an egg sandwich that has a radioactive marker in it, and then take x-rays of your back and abdomen at different time periods over two hours) was how I was dx'd but unfortunately I had an allergic reaction to Reglan and the other meds were really not an option for me.
I've increased my Prevacid dosage and eat much smaller meals throughout the day and am doing better.
You may want to ask the GI about the possibility of gastroparesis.
Diagnosed with Crohn's 5.2006 by: Capsule Endoscopy, Prometheus Labs IBD-First Step
7.2006-Dx'd with Severe CD by Colonoscopy (Have had 3 scopes in 1 year!)
Gastroparesis, Severe IBS-D
Remicade, Prevacid, Colazol, Lotronex